Various abbreviations that appear in the specification and/or in the drawing figures are defined as below:
BS Base Station
CA Carrier Aggregation
CN Core Network
DRB Data Radio Bearer
eNB evolved Node B
EPS Enhanced Packet System
EPC Enhanced Packet Core
GW Gateway
HLR Home Location Register
HSS Home Subscriber Server
MeNB Macro eNB
MME Mobility Management Entity
MSC Mobile Switching Centre
NAS Non Access Stratum
OAM Operations, Administrations and Maintenance
PDCP Packet Data Convergence Protocol
PDU Protocol Data Unit
PCell Primary Cell
ProSe Promixity Service
RAN Radio Access Network
RB Radio Bearer
RLC Radio Link Control
RRC Radio Resource Control
RRM Radio Resource Management
SCell Secondary Cell
SeNB Small Cell eNB
SRB Signaling Radio Bearer
UE User Equipment
VLR Visitor Location Register
WAN Wide Area Network
The following description of background art may include insights, discoveries, understandings or disclosures, or associations together with disclosures not known to the relevant art prior to the present invention but provided by the present invention. Some such contributions of the present invention may be specifically pointed out below, while other such contributions of the present invention will be apparent from their context.
With the rapid developments of an LTE system, a high-speed data service via low power nodes (e.g., a small cell BS) becomes increasingly important to suit the requirements of wireless communication users. It is known that the small cell BS, which is generally deployed to be closer to UEs than a macro BS in some certain areas, such as at hotspots, is capable of providing a relatively high speed data service. Therefore, how to provide ProSe communication either via direct UE-to-UE communication, or locally routed by eNB without CN involved to achieve a high speed data rate under a wireless communication system, e.g., the LTE system, has become a hot topic in the 3GPP.